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* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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*/
package org.infinispan.atomic;
import org.infinispan.Cache;
import org.infinispan.batch.AutoBatchSupport;
import org.infinispan.batch.BatchContainer;
import org.infinispan.container.entries.CacheEntry;
import org.infinispan.context.Flag;
import org.infinispan.context.InvocationContext;
import org.infinispan.context.InvocationContextContainer;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
/**
* A layer of indirection around an {@link AtomicHashMap} to provide reader consistency
*
* @author Manik Surtani (<a href="mailto:manik AT jboss DOT org">manik AT jboss DOT org</a>)
* @since 4.0
*/
public class AtomicHashMapProxy<K, V> extends AutoBatchSupport implements AtomicMap<K, V> {
private static final Log log = LogFactory.getLog(AtomicHashMapProxy.class);
private static final boolean trace = log.isTraceEnabled();
Object deltaMapKey;
Cache cache;
InvocationContextContainer icc;
public AtomicHashMapProxy(Cache cache, Object deltaMapKey, BatchContainer batchContainer, InvocationContextContainer icc) {
this.cache = cache;
this.deltaMapKey = deltaMapKey;
this.batchContainer = batchContainer;
this.icc = icc;
}
// internal helper, reduces lots of casts.
private AtomicHashMap<K, V> getDeltaMapForRead() {
return (AtomicHashMap<K, V>) cache.get(deltaMapKey);
}
private AtomicHashMap<K, V> getDeltaMapForWrite(InvocationContext ctx) {
CacheEntry lookedUpEntry = ctx.lookupEntry(deltaMapKey);
boolean lockedAndCopied = lookedUpEntry != null && lookedUpEntry.isChanged() &&
((AtomicHashMap) lookedUpEntry.getValue()).copied;
if (lockedAndCopied) {
return getDeltaMapForRead();
} else {
// acquire WL
boolean suppressLocks = ctx.hasFlag(Flag.SKIP_LOCKING);
if (!suppressLocks) ctx.setFlags(Flag.FORCE_WRITE_LOCK);
if (trace) {
if (suppressLocks)
log.trace("Skip locking flag used. Skipping locking.");
else
log.trace("Forcing write lock even for reads");
}
AtomicHashMap map = getDeltaMapForRead();
// copy for write
AtomicHashMap copy = map == null ? new AtomicHashMap(true) : map.copyForWrite();
copy.initForWriting();
// reinstate the flag
if (suppressLocks) ctx.setFlags(Flag.SKIP_LOCKING);
cache.put(deltaMapKey, copy);
return copy;
}
}
// readers
public Set<K> keySet() {
return getDeltaMapForRead().keySet();
}
public Collection<V> values() {
return getDeltaMapForRead().values();
}
public Set<Entry<K, V>> entrySet() {
return getDeltaMapForRead().entrySet();
}
public int size() {
return getDeltaMapForRead().size();
}
public boolean isEmpty() {
return getDeltaMapForRead().isEmpty();
}
public boolean containsKey(Object key) {
return getDeltaMapForRead().containsKey(key);
}
public boolean containsValue(Object value) {
return getDeltaMapForRead().containsValue(value);
}
public V get(Object key) {
return getDeltaMapForRead().get(key);
}
// writers
public V put(K key, V value) {
try {
startAtomic();
InvocationContext ctx = icc.createInvocationContext();
AtomicHashMap<K, V> deltaMapForWrite = getDeltaMapForWrite(ctx);
return deltaMapForWrite.put(key, value);
}
finally {
endAtomic();
}
}
public V remove(Object key) {
try {
startAtomic();
InvocationContext ic = icc.createInvocationContext();
return getDeltaMapForWrite(ic).remove(key);
}
finally {
endAtomic();
}
}
public void putAll(Map<? extends K, ? extends V> m) {
try {
startAtomic();
InvocationContext ic = icc.createInvocationContext();
getDeltaMapForWrite(ic).putAll(m);
}
finally {
endAtomic();
}
}
public void clear() {
try {
startAtomic();
InvocationContext ic = icc.createInvocationContext();
getDeltaMapForWrite(ic).clear();
}
finally {
endAtomic();
}
}
@Override
public String toString() {
return "AtomicHashMapProxy{" +
"deltaMapKey=" + deltaMapKey +
'}';
}
}